Hi

I had no choice in the matter for quite a while, so I would have to say yes as well.
Compared to the tying threads I have now, the sewing thread is just as strong.
Colours and price is a big bonus, thread build-up on smaller hooks is the downside.
My most successfull panfish (and the occasional carp) fly is made from nothing more than dayglo green or orange sewing thread, red wool or flash for a tail and superglue to keep the lot together. I slip on a glass bead, tie a conical body (like a popper) with glue between the layers. Final step, believe it or not is crushing the bead...
The success of that fly means I'll never not have sewing thread close to hand.

Cheers